Ferrous base copper molybdenum age hardening alloy and method



United States Patent 'Oflice Patented July 2, 1968 ABSTRACT OF THE DISCLOSURE Ferrous base copper alloys and a method for producing hardened products of the same, the alloys being capable of being hot worked, and of being age hardened to a high strength level at which ductility is remarkably retained, and the alloy composition is defined to come within consisting essentially of about 4.0% to approximately 7.0% copper, about 0.8% to about 2.5 molybdenum, an additive amounting from about 0.2% to about 1.0% in total of at least one element of the group consisting of aluminum, silicon, titanium and circonium, manganese from a trace up to about 1.0%, carbon from a trace up to about 0.1%, sulphur and phosphorus each from a trace up to about 0.04%, and the balance iron.

This invention relates to ferrous base alloys and more especially is concerned with new and useful ferrous base alloys in which copper is supplemented to contribute age hardening and other worthwhile properties, and the invention further is concerned with the production of ferrous base copper alloys and products which in having copper supplemented as indicated are age hardened.

An object of the present invention is to promote hot workable ferrous base copper age hardening alloys in which the strength level after aging is higher than can be expected for the given amount of copper, and ductility at the relatively high strength level stands improved in view of composition of the alloys.

Another object herein is the provision of ferrous base copper alloys of the character indicated in which remarkably large increases in yield strength and ultimate tensile strength can be caused to occur through age hardening, and ductility is appreciably. retained.

A further object of this invention is the provision of ferrous base copper alloys which from the standpoint of production and alloy content are practical, the alloys moreover having favorable hot working properties and being quite satisfactorily responsive to stabilizing heat treatment and well suited to' being worked through such operations as machining, punching, bending, and the like, at much lower temperatures than the hot working and solution heat treating temperature, thereafter having good aging response for being hardened to much higher strength levels and upon being age hardened having remarkable retention of ductility in view of the particular strength level attained by the alloy.

Another object herein is the provision of a method for producing age hardened alloy articles and products using ferrous base copper alloys of the character indicated.

Other objects of the present invention in part will be obvious and in part more fully pointed out in the course of the disclosure which follows:

The invention accordingly resides in the combination of elements, in the composition of materials, in the several operational steps, and in the relation of each of the same to one or more of the others as described herein, the scope of the application of which is indicated in the claims at the end of this specification.

As conducive to a clearer understanding of certain features of the present invention it may be noted at this point that in many industrial practices it becomes desirable to subject an alloy to hot working operations, and later to forming and other fashioning operations such as at about room temperature before finally hardening the alloy, thus first to take advantage of the working properties of the alloy before hardening and then carry through to obtain a hardened and strengthened product. Some of the age hardenable alloys heretofore known have been subjected to hot working operations such as forging, rolling, or the like, at the elevated temperatures to which the alloys should be heated for the purpose, and it has become quite apparent that the particular alloys are so hot short as to severely crack and therefore compositionally are not suited to have favorable hot working properties.

There are age hardening alloys which are sufficiently soft in the solution heat treated condition thereafter to permit machining and other working, forming or fabricating steps before being age hardened at temperatures which are significantly lower than the solubilizing temperatures. Through the use of the lower temperature age hardening treatment the articles and products fashioned from the relatively soft solution heat treated alloys are increased in hardness by a de-solubilizing effect which notably avoids any need for reheating the alloys to the severely high solubilizing temperatures. Despite the advantages which are inherent in the latter feature, certain age hardenable alloys unfortunately have but mild response to aging treatment and therefore an increase in strength much above the strength level in the solution heat treated condition of the alloys is not possible through aging.

In other age hardenable alloys heretofore known the aging response is adequate for increasing the hardness of the alloy upward within a very considerable range from the hardness values in the as solution heat treated condition, but with these increases ductility too readily is sacrificed in the hardened alloy.

An outstanding object of the present invention accordingly is to achieve a ferrous base age hardening alloy which compositionally, and considering that iron predominantly is to be a constituent, is practical for satisfying many and various needs within sensible limits on cost of material, and which alloy compositionally is highly effectively balanced to be capable of being hot worked, fashioned into articles and products at temperatures much below solution heat treating temperatures and thereafter of being aged with good aging response upon being held reheated at relatively low temperatures and of retaining a worthwhile amount of ductility after aging.

Referring now more particularly to the practice of the present invention, it is found that ferrous base alloys containing about 4.0% to approximately 7.0% copper, approximately 0.8% to about 2.5% molybdenum, and further containing an additive amounting from about 0.2% to about 1.0% in total of at least one element of the group consisting of aluminum, silicon, titanium and zirconium, and the remainder substantially all iron, are not only age hardenable but the alloys are amenable to hot working, can be worked in the as solution heat treated condition at room temperature and at other temperatures much below solutioning temperatures, and furthermore the alloys have strength levels which are enhanced by the molybdenum, high aging response, and tend well to retain ductility from being age hardened. Small supplemental amounts of tolerable other constituents may of course also be present in the alloys, among these constituents for example being manganese from incidental amounts up to about 1.0% maximum, and phosphorus, sulphur and carbon each from a trace up to about 0.1% maximum. Manganese tends to raise the level of hardness of the matrix whether the alloys are in the as solution heat treated condition or are in the aged condition, and moreover counteracts adverse effects of such elements as sulphur. The phosphorus, sulphur and carbon are regarded as impurities and, though permissible each up to about 0.l%, preferably are kept from a trace up to about 0.04% maximum in the instance of each of sulphur and phosphorus and from a trace up to about 0.05% maximum in the instance of carbon so that in view of the latter the alloys are substantially carbonless.

The additive of one or more of the elements of the group consisting of aluminum, silicon, titanium and zir conium promotes hot working properties and freedom from hot shortness and in this respect shares with molybdenum which itself tends slightly toward improving the hot workability of the alloys. Copper and any one or more of the alloying additions of aluminum, silicon, titanium and zirconium share by gOing into solution at the solution heat treating temperatures and ultimately cooperate so as to produce an age hardening effect and high response to aging and meanwhile the molybdenum tends slightly toward increasing the aging response and quite appreciably raises the strength level of the alloys before and after the alloys are aged. The molybdenum constituent notably imposes a factor to which improved retention of ductility by the alloys after aging is attributed. As the amount of addition agent from the group consisting of aluminum, silicon, titanium and zirconium is decreased to amounts quite appreciably outside the more general composition limits herein hot shortness is encountered and high response to aging is sacrificed, while an increase in the amount of the addition agent quite appreciably upward from these same limits is conducive to excessive brittleness after age hardening. Substantially smaller amounts of copper outside the more general composition limits referred to promote reduced ductility and diminish the aging response, while substantially larger amounts of copper outside these same limits lead to hot shortness.

Ferrous base age hardenable alloys within the above group and preferred because of such reasons as being exceptionally well within being balanced toward having hot workability, high aging response and the molybdenum-enhanced strength levels with retention of ductility after aging, are those alloys which contain about 4.25% to about 7.0% copper, from approximately 1.0% to about 2.0% molybdenum, an additive amounting from about 0.2% to approximately 0.7% in total of at least one element of the group consisting of aluminum, silicon, titanium and zirconium, and the remainder of the alloy being substantially all iron, except for small supplemental amounts of tolerable other constituents as the case may be, among these being manganese from incidental amounts up to about 1.0% maximum, phosphorus and sulphur from trace amounts up to about 0.04% each and carbon from trace amounts up to about 0.05%.

For the present alloys to be hardened by aging, the alloys are heated at solution temperature until solid solution saturated with copper, molybdenum and additive of at least one element of the group consisting of aluminum, silicon, titanium and zirconium is obtained, the heating being in a range of about l500 F. to about 1875 F. for a period of time which usually is about one-quarter of an hour to about two hours or more depending upon such factors as the temperature selected and the particular shape and size of the alloy metal body which is being treated. Most practically, solution temperatures beginning in the environs of about 1600 F. and ranging upward are used except where carbon in the alloys exceeds about 0.05% and then temperatures relatively low in the more general solution heat treating temperature range are preferred. As solution treating temperature is increased in the range the solubility of copper increases and copper, molybdenum and additive of at least one element of the group consisting of aluminum, silicon, titanium and zirconium go into solution. Accordingly through relying upon a proper solution ternperature or temperatures and corresponding solubility factor with respect to time, the hardness, yield strength and ultimate tensile strength of the alloys are readily controlled, bearing in mind the hardness and strength in the as solutioned and cooled condition, prior to aging, increase with the amounts of copper, molybdenum and additive already identified which are then in solution. Should carbon be present in the alloy toward the upper tolerable limit of about 0.1% carbon, the solution heat treating temperature is best maintained on the low side in the aforementioned solution temperature range to avoid excessively high hardness after quenching particularly where the metal is to be worked in the as solutioned and cooled condition.

The alloys of the present invention, being amenable to hot rolling and to any of a host of other forms of hot working at elevated temperatures, are so worked as occasion may demand, thus producing any such products as forgings, sheet, strip, tubing, rods, bars, I-beams, channels, rails, or the like. The optimum hot working temperatures fall within the solution temperature range, and are about 1600 F. to about 1800 F. Following the solution heat treating stage, the alloys are quenched preferably to about room temperature in a liquid coolant such. as oil or water, or in a gaseous coolant such as air. In accordance with preferred practice the alloys are hot worked, then solution heat treated, and the solution heat treatment is followed by a rapid quench of the heat treated alloys as in oil or water to about room temperature. An appreciably more rapid quench than cooling in air at usual room temperature is preferred, for the amounts of copper and additive of the group consisting of aluminum, titanium, zirconium and silicon in solid solution from the solution heat treatment tend to be less effectively retained in solution through slowly cooling the alloy in air. Nevertheless, in practices still in accordance with the present invention, adequately favorable results for certain purposes are had through heating the alloys to hot working temperature and concurrently achieving solution treatment, the solution heat treated alloys then being hot worked and cooled through hot working and in air at ordinary room temperature or more rapidly until room temperature is reached.

Alloys within the more general composition limits hereinbefore set forth and in the solution heat treated and quenched condition have ductility, cold workability and further characteristically have hardness levels which are considerably short of their full potential on hardness. At this stage, therefore, the alloys are often fabricated, thereby producing articles and products of the alloys by any one or more such shaping operations as cutting, punching, machining, or the like under the advantage of the existing favorable properties of the alloys. These operations of course may be performed at ordinary room temperature or at other low temperatures which do not materially alter the solution heat treated and quenched condition of the alloys. Thereafter, to harden the alloys, such as the alloy metal in the aforementioned articles and products, the metal is brought up to aging temperature in an aging heat which endures long enough to bring copper and additive from the group consisting of aluminum, titanium, zirconium and silicon out of solution and into dispersed fine form throughout the alloy. The heating for aging is conducted at a temperature in the approximate range of 500 F. to 1000 F, though toward expediting the aging heat treatment, temperatures upward from about 700 F. to 1000 F. are preferred. The alloys are capable of being aged to attain their maximum strength and hardness levels without being highly sensitive to over-aging. There are of course occasions where the aging heat treatment is used to roduce a desired level of hardness and strength with commensurate ductility, which level is below the full potential on hardness and strength with commensurate ductility, but in any case there is ever a tolerable latitude with respect to length of aging time corresponding to the temperature selected, though this latitude diminishes as the temperature within the range is increased. Size and shape of the articles and products also may cause adjustments to be made in length of the aging period; however, average duration of the aging treatment toward developing maximum hardness and strength with commensurate ductility at about 500 F. is usually somewhere in the vicinity of about 25 hours or more and a like average period of time for aging the alloys at approximately 1000 F. is somewhere about /2 hour to about 1 hour. For example, either aging at 700 F. for about 3 to 10 hours or at 900 F. for about 1 hour to about 5 hours are typical temperature-time relations which are observed in the context of developing maximum hardness and strength with commensurate ductility. The aging treatment is terminated by bringing the aged alloys down to the environs of room temperature from the aging temperature. This for example is either by air cooling or by more rapidly quenching such as in oil or water.

With adequate amounts of copper, molybdenum and additive of at least one element of the group consisting of aluminum, silicon, titanium and zirconium in solution the present alloys have a remarkable response to the age hardening heat treatment in the sense that the hardness, yield strength and ultimate tensile strength levels all can be made to increase remarkably through properly aging the alloys. The molybdenum contributes to higher strength levels of the alloys before and after the aging heat treatment and reserves ductility in the alloys after aging even though the ductility as observed does apply to the higher strength level by which the alloy is characterized through having molybdenum present. The alloys are easily and readily solution heat treated in the manner hereinbefore described to introduce enough copper, molybdenum, and additive of at least one element of the group consisting of aluminum, silicon, titanium and zirconium in solid solution for the alloys as solutioned and cooled to have strength levels available to be raised in excess of at least about 20,000 p.s.i. both with regard to yield strength and ultimate tensile strength through age hardening and still have the alloys ductile. Full potentials for these increases in yield strength and ultimate tensile strength in many of the alloys are enormous and sometimes the increases in each of yield strength and ultimate tensile strength do amount to as much as 60,000 p.s.i. or more with the aged alloy still ductile. These good properties are had over and above the fact that the alloys may be satisfactorily hot worked and be brought to lower temperatures in the solution heat treated condition and then be further worked at these lower temperatures by any of a variety of operations among which illustratively are machining, punching and other forms of cutting as well as bending, stamping, or the like. The alloys therefore are readily shaped into articles and products which as often as desired are thereafter age hardened in accordance with use of an aging heat which has already been described.

In producing the alloys herein, an open hearth furnace preferably is utilized for meeting large tonnage demands, though other furnacing equipment instead is also satisfactory, as for example an electric arc furnace especially where smaller tonnage production is to be accomplished. For maintaining carbon level within the limits desired in the alloy, an oxygen process is found to be advantageous particularly if high-carbon charging stock is used and thus initially introduces very considerable quantities of carbon in the melt. For example, if need be the electric arc furnace process is adapted to an oxy-process for adjusting the carbon content to within tolerable amounts as by use of an oxygen lance during refining.

As illustrative of a production technique employed, a Herault type direct-arc furnace of about 50,000 pound rated capacity and having a basic lining is employed. Usually an initial charge of somewhere in the general vicinity of 40,000 pounds is introduced in the furnace, electrolytic copper for example being present in amount of about 2,400 pounds and there additionally being about 36,770 pounds of low-carbon, low alloy steel scrap with sufficient iron ore to reduce the carbon content appreci1 ably during carbon boil. If the alloy content of the steel scrap is relatively high, the quantity of steel scrap in the charge is diminished in favor of adding ingot iron inreplacement of the scrap. The amount of iron ore present is varied and depends upon such factors as the initial carbon content of the scrap and the characteristics of the particular furnace used. Upon completion of the initial charging, the arcs of the furnace are struck and melting of that portion of the charge next to the electrodes is promoted under relatively low power. After a pool of molten metal is obtained near the electrodes, the power then is increased to accomplish very rapid melt down of the charge. During melt down and during a period immediately following melt down, oxidation of the carbon and other reactive alloying elements occurs. In order to prevent phosphorus reversion during the oxidation or refining period, it is helpful to make additions of 0210, which material maintains a basic slag over the melt. The copper charge is largely unaffected by the bath reactions, and virtually no copper loss is to be expected. This is notable in taking first samples for analysis, though mainly the analysis is made to determine carbon, manganese and oxidizible elements contents.

The refining process sometimes is carried out as a double slagging operation, in which event the slag without any initial additons of CaO is first allowed to become oxidizing, and then the furnace power is turned off, the electrodes raised, and the slag is thoroughly raked out. Thereafter, another charge is made, this consisting of about -5 parts C210, '1 part fluospar, and 1 part sand, which becomes the second slag and of course is basic. If the sulphur content is found to be above say about 0.04% an addition of ferromanganese is advantageously made to tie up sulphur as manganese sulfide. The electrodes are lowered, the power turned to a high setting for rapid reheating and a short refining period at high temperature of about 2900" F. to 3000 'F. ensues. At this point a second sample is taken for analysis, mainly to determine whether carbon, sulphur and phosphorus contents are within tolerable limits. A satisfactory determination in this respect is followed by making final additions. For an alloy in which nominally a silicon content of about 0.3% and a molybdenum content of about 1.0% are for example desired, the melt is first deoxidized preferably with approximately pounds of high-impurity aluminum, and then about '160 pounds of low-carbon ferrosilicon (76% Si) and 668 pounds of low carbon term-molybdenum (60%) are added.

These additions are in amounts adjusted to account for predicted melting losses of silicon and molybdenum. Within about 10 minutes from making these additions, the furnace is tapped into the ladle and during tapping still another 100 pounds of high impurity aluminum is added, this to the metal stream for final deoxidation. This total charge in the furnace thus illustratively yields an alloy containing about 6.0% copper, 1.0% molybdenum, 0.3% silicon, 91.7% iron, and other elements up to about 1% total, among which are phosphorus and sulphur each not exceeding about 0.04%, carbon not exceeding about 0.05% and the remainder mainly being manganese, chromium and nickel from the steel scrap of the charge. Of course, any one or more of the addition elements aluminum, silicon, titanium and zirconium may be used singly as in the instance of silicon hereinbefore described or these addition elements may be used in combination; however, in each case about 200 pounds of aluminum are added for purposes of deoxidation. Should aluminum be desired for deoxidizing or should either or both aluminum and zirconium be desired as an additive these elements conveniently take the form of the pure metal. Where one or more of silicon and titanium are to be used as additives they are quite suitably in low carbon ferroalloys charged into U area and bend tests after aging, and the results of these tests also appear in the table and are indicative of quite favorable ductility, particularly in view of the strength level.

Solution As Aging Aged 0.2%, Off- Ult. Tens. Elong. Reduc- Alloy Composition (Percent) Treatment, Solutioned Treatment, Hardness sot Yield Strength, in 2 in., tion Of Bond Test F., Time Hardness Time Rockwell Str., p.s.i. p.s.i. Percent Area,

Rockwell Percent A 6.73 Cu, 1.49 MO., 028 Si 1,650, g C20 )1, 750 108, 625 8. 5 45 Ductile. d 1, 650, X), C20 143, 500 149, 250 7. 0 38 D0. 1, 850, A C31 118, 000 140, 000 6. 0 34 D0. 1, 850, C31 187, 500 191,000 4. 0 30 D0. 1, 650, E6 B00 74, 300 88, 000 11. 33 D0. 1, 650, A B90 130, 750 137, 000 10. 5 38 D0. 1, 850, C17 94, 000 104, 000 7. 0 39 Do. 1, 850, /3 C17 156, 500 162, 000 5. 5 20 D0. 1, 650, h 1389 69, 000 82, 700 14. 5 43 D0. 1, 650, B89 900, 2 hr C33 123, 000 132, 300 11. 5 36 D0. 1,850, V C10 900, 2 hr.--" C38 D0. 1, 650, B85 9. 0 50 Do. 1, 650, /2 B85 7. 5 47 D0. 1, 850, V C19 7. 5 39 Do. 1,850, C19 8. 0 35 D0. 1, 650, A; 1393 10. 0 57 D0. 1, 650, B93 13. 5 47 Do. 1, 850, C 6. 3 40 Do. .do 1,850, hr C25 5 8 35 Do. F 4.57 Cu, 2.72 l\/Io, 0.71 Si. 1, 650, C85 900, 4 hr Do. do 1, 850, 026 900.4 hr Do.

the melt. From the ladle the melt is poured into molds which in size and shape may depend upon the particular product which is to be produced from the billet or ingot. Carbon is neither necessary nor desirable in the age hardenable alloys though it occurs and is kept within tolerable limits as a contaminant.

Test results on a number of alloys within the composition limits hereinbefore identified are given in Table I with reference to Alloys A to F, inclusive, which alloys in each instance in addition to the copper and molybdenum contents noted with the additive of at least one element of the group consisting of aluminum, silicon, titanium and zirconium, further were compositionally within limits of manganese less than about 1.0% maximum, carbon from traces up to about 0.03% maximum and phosphorus and sulphur each from traces up to about 0.04% maximum, the remainder being substantially all iron. 'Billets of all of the alloys noted were heated to temperatures within the range of 1700 F. to 1800" F. and while thus heated were hot worked and showed quite favorable hot working properties in producing strip of the alloys. Following upon the hot working operations, including hot rolling, the resulting strip of each of the alloys was solution heat treated. A batch of the alloy strip of each of the alloys was solution heat treated at about 1650 F. While another batch of strip of each of the alloys was solution heat treated at about 1850 F., the duration of the treatment in each instance being about one-half hour at the solution temperature. The strip was rapidly quenched from the solution temperature to room temperature, Samples of the solution heat treated and cOOled alloys were cut from the strip and tested to obtain as-solutioned hardness values, and yield strength and ultimate tensile strength corresponding to the same as-solutioned condition of the metal, all of which values are noted in the table. Further, certain of the samples of each of the alloys, from each of the solution heat treatments indicated, were aged at about 900 F. for the periods of time which appear opposite the aging temperature in the table. The latter samples then were cooled from the aging temperature to room temperaure and thereafter were tested for hardness and with the exception of alloy F were also given tests for yield strength and ultimate tensile strength in the age hardened condition. It will be seen that the increases in hardness and strength of the alloy samples through aging are large. The hardness values for Alloy F were relied upon as being indicative of strength and aging response. Some of the samples of all of the aged alloys furthermore were subjected to elongation, reduction of For the amount of copper present in the tabulated alloy compositions, the hardness and strength levels of the alloys are remarkably high and ductility which the alloys retain through aging stands improved with reference to the actual hardness and strength levels of the age hardened alloys, The aging response moreover is remarkably good and so are the hot working properties.

Accordingly it will be appreciated that in the present invention ferrous base copper molybdenum alloys and a method are provided through which the various objects noted together with many thoroughly practical advantages are successfully achieved. The alloys have a sufiiciently low alloy content to offer an attraction in this respect with further important advantages among which are favorable hot working properties, sensible hardness ranges in the as-solutioned and cooled condition and favorable working properties in the latter condition, remarkable strength levels for the amount of copper at hand, excellent aging response characteristics, and the molybdenum-enhancing effect upon ductility so as to retain ductility notably with reference to the strength level following the aging heat treatment.

As many possible embodiments may be made of this invention and as many changes and modifications may be made in the embodiments disclosed, it will be distinctly understood that the foregoing disclosure is to be considered as illustrative, and not as a limitation.

We claim:

1. A hot workable ferrous base copper age hardening alloy consisting essentially of about 4.0% to approximately 7.0% copper, about 0.8% to about 2.5% molybdenum, an additive amounting from about 0.2% to about 1.0% in total of at least one element of the group consisting of aluminum, silicon, titanium and zirconium, manganese from a trace up to about 1.0%, carbon from a trace up to about 0.1%, sulphur and phosphorus each from a trace up to about 0.04%, and the balance iron.

2. In the production of a hardened ferrous base copper alloy product, the art which includes, providing a ferrous base copper alloy consisting essentially of about 4.0% to approximately 7.0% copper, about 0.8% to about 2.5% molybdenum, an additive amounting from about 0.2% to about 1.0% in total of at least one element of the group consisting of aluminum, silicon, titanium and zirconium, manganese from a trace up to about 1.0%, carbon from a trace up to about 0.1%, sulphur and phosphorus each from a trace up to about 0.04%, and the balance iron, heating said alloy at solid solutioning temperature for a sufficiently long period of time and cooling the alloy for the solubilized alloy potentially to increase in strength level by at least about 20,000 p.s.i both with regard to yield strength and ultimate tensile strength upon being aged within the approximate temperature range of 500 F. to 1000 -F. and thereafter be ductile, working said solubilized alloy and forming an age hardenable product of said solubilized alloy, and heating said solubilized alloy product within the temperature range of 500 F. to 1000 F. for a period of time long enough for said alloy product as aged to have increased in yield strength and ultimate tensile strength by amounts each exceeding about 20,000 -p.s.i. and be ductile.

3. An age hardened ferrous base copper alloy consisting essentially of about 4.0% to approximately 7.0% copper, about 0.8% to about 2.5% molybdenum, an additive amounting from about 0.2% to about 1.0% in total of at least one element of the group consisting of aluminum, silicon, titanium and zirconium, manganese from a trace up to about 1.0%, carbon from a trace up to about 0.1%, sulphur and phosphorus each from a trace up to about 0.04% and the balance iron, with said alloy being ductile and characterized by a yield strength and an ultimate tensile strength each exceeding the comparable strength of the alloy as solutioned and cooled prior to aging by at least about 20,000 psi.

4. A hot workable ferrous base copper age hardening alloy of claim 1, wherein the amount of carbon is within up to about 0.05% maximum.

5. A hot workable ferrous base copper age hardening alloy of claim 1 wherein said copper in amount is within about 4.25% to 7.0%, said molybdenum in amount is within approximately 1.0% to 2.0%, and said additive in amount is within about 0.2% to 0.7%.

6. A hot workable ferrous base copper age hardening alloy of claim 5, wherein the amount of carbon is within up to about 0.05% maximum. 7

7. In the production of a hardened ferrous base copper alloy product as set forth in claim 2, wherein said carbon in amount is within up to about 0.05% maximum.

8. In the production of a hardened ferrous base copper alloy product as set forth in claim 7, wherein said copper in amount in said alloy is Within about 4.25% to 7.0%, said molybdenum in amount in said alloy is within approximately 1.0% to 2.0%, and said additive in amount in said alloy is within about 0.2% to 0.7%.

9. An age hardened ferrous base copper alloy of claim '3, wherein the amount of carbon is within up to about 0.05 maximum.

10. An age hardened ferrous base copper alloy of claim 3, wherein said copper in amount is within about 4.25% to 7.0%, said molybdenum in amount is within approximately 1.0% to 2.0%, and said additive in amount is within about 0.2% to 0.7%

11. An age hardened ferrous base copper alloy of claim 10, wherein the amount of carbon is within up to about 0.05 maximum.

References Cited UNITED STATES PATENTS 1,835,667 1-2/ 193 1 Nehl 148-142 1,972,241 9/ 1934 Lorig et a1 148-142 1,972,248 9/1934 Smith 148-142 X 1,976,341 110/1934 Harris 148-36 X 2,206,847 7/ 1940 Lorig 148-36 X 2,950,968 8/1960 Culp -125 3,070,438 112/1962.- Kenneford 75-125 3,136,665 6/1964 Culp 75-125 X CHARLES N. LOVELL, Primary Examiner. 

